The SDAC research plan has two parts: 1. Assessment Study. We plan to study the prevalence and patterns of drug abuse in 360 chronic mentally ill (CMI) individuals by using a comprehensive drug abuse assessment battery. 180 of the CMI are already enrolled in a 7 year prospective psychiatric study which has collected a wealth of data, but not on drug abuse. The other 180 CMI are seeking substance abuse treatment. This study will describe the association of drug abuse and sociodemographics, psychopathology, family history, and clinical course. 2. Treatment Study. We plan to assess the efficacy of innovative treatment approaches for schizophrenic cocaine abusers, including a double blind pharmacotherapy trial comparing adjunctive desipramine versus placebo in the context of a comprehensive treatment program.